“Planetary nebulae are glowing shells of gas around white dwarfs,” according to the standard explanation. This is a better description of dogma than of the image.

“Astronomers have long debated how these symmetric jets could be created,” the press release continues. “Stars are spherical”; the jets not so much. In fact, not at all. But astronomy has a long history of not letting facts get in the way of good explanations.

The nebula is “likely to have…two white dwarfs at its centre…. As the stars aged, they expanded…, one…sucking material from its companion. This material [formed] an accretion disc.” Gravitational interaction with the binaries caused the disc to precess, or wobble, and the wobbling disc then shaped the jets into knotted twists. The observations “combined…with existing computer modeling to explain in detail for the first time how these bizarre shapes came about.”..............